Kaufman george falk



K. G. FALK AND E. M. FRANKEL.

METHOD 0F PRESEBVING Foo'n.

APPLICATION FILED JAN. 30. 1918.

Patented July 8, 1919.

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VVVV fr INVNTORS ATTORNEYS y WTE@ STES ATENT QFFICE@V MUMN GERGE FALK N'D EDWARD M. FRANKEL, QF NEW YORK, N. Y., ASSIGNORS EG Wl'ilm G. LYLE, TRUSTEE, @E NEW YGRK, N. Y.

METHGD 0F PRESERVNG- EOD.

Specification of Letters Eatent.

Application led. aniiary 30. 1918. Serial No. 214.449.

To all wiom t may conce/rn:

Be it known that we, KAUFMAN Guiones FALK and EDWARD lvl. FRANKEL, citizens of the United States, residing at New York, in the county of New York and State of `New York, have invented certain new and usetul Improvements in Methods of Preserving Food, of which the following is a specification.

The principal object of our invention 1s to provide a new and improved method by which food may be advantageously preserved by drying it. rlhis and other objects of our invention will be made apparent in the following specification and claims taken with the. accompanyingdrawing, in which one specific embodiment of our invention is disclosed. 1t will be understood that modifications may be made within the scope of our invention.

Hitherto it has been found generally impracticable to preserve meat by drying it without first subjecting the nient to the action of seine preservative agent. For example, so-called dried beef is beef that has first heen corned or otherwise treated with a preservative. Hams and bacon are dried by being smoked, but the smoke oo ntains preservative agents which are essential in the process. When it has been attempted to drv meat directly, one difficulty that has been 'experienced was that before the dry'- iiip; could be carried far enough, decomposition diie to the presence of bacteria or other forms of life would set in and defeat the aim, 1f it was attempted to hasten the process by raising the temperature this would not only promote the development ot the bacteria, but if the temperature were raised too high the meat would cook, or its composition be changed, or the fats in the meat would melt and prevent further drying, and moreover become rancid. Attempts have also been made to dry mea-t by a vacuuni process, but failure has resulted from such e'orts because the drying cannot be accomplished merely by maintaining' a vacuum but the proper application of heat must be made at the same time and there are conditions which reqnire especial care to be given in this connection.

l ll've will now explain one specitlc course of procedure for drying meat that may be taken as illustrative of our invention. The accompanying drawingwill be referred to, but this is highly diagrammatic and intended primarily to aid in iixing the ideas that are involved.

1n the vacuum chamber 11 is a series of shelves 1G of heat conductive material, each shelf being hollow so that wai-ni water may be iliade to circulate Ithrough it as will be pointedoutpresently. @n the shelves 16 are placed movable trays 13 sliding in and out of the vacuum chamber 11. The trays 13 are made of good conducting non-corrosive metallic frames over which a wire gauze is fastened for a purpose t0 be pointed ont presently. 0n the wire gauze are placed slices of fresh meat 17 or pieces cut in cubes as indicated by the reference character 17.

The shelves are connected by suitable piping with a centrifugal pump 19 which causes the water to circulate passing through the heater 21, hollow shelves 16 in vacuum chamber 11 and back to the pump 19 as indicated in the drawing.

rlhe vacuum is maintained in the chamber 11 by means of the air and Vapor plump 27 drawing through the pipe 2G which opens at 25 into the chamber 11 and the exhausted air and vapor are. passed through the condenser 33 which removes the greater part of the aqueous vapor and the remaining air and vapor is delivered from the pump The vacuum chamber 11 has a door 18 which may be moved aside and the trays moved out and the dried meat removed therefrom and a supply of fresh meat put in place.

Of course any suitable means may be employed for creating or maintaining the vacuum, and in most cases, as in preserving meat for eXaiii-ple, it is important to avoid breaking the vacuum, or otherwise unduly exposing the substance to air, during the heating process.

After loading; the trays up with fresh, meat they are pushed back into the chamber 11, the door 18 is closed, and warm water is circulated through the hollow shelves 16, the temperature being kept by the heater 21 so that in the shelves 16 it is at about G0o C. or a little below this limit. By means of the metallic frames and wire gauze of the trays 13, the heat is conducted to the meat and the temperature thereof raised to that of the trays and shelves. At the same time the air exhausting pump 27 is kept in operation so as to maintain a vacuum in the chamber 11 corresponding to about two inches of mercury. The temperature may be observed through a window in the wall ofthe chamber `11 as registered by a thermometer within, and the pressure may be observed by means of the gage 32. The meat being raised from the shelves by means of the gauze supports, evaporation downward as well as in other directions is permitted, and thus the time required'tor evaporation is reduced.

At the pressure and temperature stated, water will boil; that is, an open vessel of water in the chamber 11 maintained at the temperature of 60o C. would boil with the pressure in the chamber maintained at or below two inches of mercury. Of course, the meat juice is a water solution of a variety of substances together with a colloidal protein solution; and its vapor pressure is not substantially different from that of pure water. Heat at the temperature mentioned is communicated readily by directI conduction to the pieces of meat 17 and 17', and the effect is practically to boil the moisture out of the meat, but of course this is accomplished without the effects commonly due to boiling meat, because when meat is boiled in the open air it is at a temperature of approximately 1000 and this temperature effects important changes which are entirely absent at 60 C. The moisture driven out of the meat in this way forms a Vapor in the chamber 11, but this is condensed at 33 and then continually drawn off by the pump 27. By working within the limits of temperature and pressure stated the growth of bacteria during the process is not promoted and the drying is ei`ected before any bacterial or chemical decomposition takes place. Moreover, below the temperature of 60o in the substantial absence of air the fats in the meat are not mel-ted and do not become rancid. By the removal of water the concentration of salts is increased and their preservative .eiect is secured without the addition of any external preserving agent. Within the temperature and pressure limits stated no cornified layer is formed on the surface of the meat as might be the-case for drying at a higher temperature. The chemical composition of the meat is substantially unchanged, the only change being the removal of water. Ordinary fresh meat consists of about of water and of this quanti-ty about 65% on the whole is removed, leaving 10% of water on the original whole in the meat or about 29% of water in the dried product. Bacteria do not develop with so small a percentage of water in the medium. Salt concentration also is unfavorable for bacterial growth.

The physical character of the sections ot' 7 the meat is also of some importance. For best results the direction of cut should be vlongitudinal with the fiber instead of transverse. Longitudinal cutting favors the evaporation of water from the cells in the 7 interior, due to spreading of liber on drying.

iVith our improved process the meat can be trimmed of bone and fat, &c., immediately after 'slaughtering and sent to the vacuum drier without cooling it; indeed the retention of the animal heat is of advantage. Hence, it will be seen that the procedure saves delay and avoids the disadvantage of storage of the freshmeat and particularly there is no necessity for cold storage. The shipment of bone and fat from the slaughter house is made unnecessary and also the shipment of large water content in the meat is avoided. After the meat is dried it can be packed in any suitable manner to keep it clean as, for example, wrapped in paraiin paper, and shipped. When it is to be used it can be readily soaked up in a short time in water. To be cooked by stewing, the dried meat .may be put directly in the. hot water. Steaks may be soaked up in a small quantity of temperate water and will become like fresh steaks readyfor broiling.

In the specication'and claims the term meat is not used in the narrow sense only, but is intended to include sh, hides, skins and the like.

We claim:

1. The process of preserving meat, which consists in cutting it up and removing bon-e, excessive fat, etc., and placing it in a vacuum chamber immediately after slaughtering and without cooling, then heating it and maintaining its temperature at or a little belowr 60 C. by conduction of heat thereto from a contacting member, thereby driving oiil the moisture in said meat, maintaining the vacuum meanwhile, and in this way drying the meat without melting the fatty elements nor making them rancid and without accelerating bacterial growth and without decomposition of the proteins and without producing a cornied exterior layer, and thus preserving the mea-t by the removal 1 of water therefrom and the resultant increase' of salt concentration therein.

2. The process of preserving-meat which comprises subjecting the same to a degree of vacuum suliicient to lower the boiling point l of the water in the meat to va temperature below that at` which the protein in the meat coagulates, heating themeat toa temperature approximately the same as the said boiling point so established, and maintainl ing said vacuum and heat simultaneously While subjecting it to a degree of vacuum for a time suicient to dry said meat of a such that water of that temperature and 10 substantial part of its water content. pressure would boil, 'continuing this treat- 3. The process of preserving food which ment until the food is thoroughly dried in 5 consists in putting it in a closed chamber readiness for removal from the chamber to drier with its normal content of moisture, be paked for shipment or storage. drying it at a determined temperature be- IQAUFMAN GEORGE FALK. 10W that which will cook the food, mean EDWARD M. FRANKEL. 

